Split input into buffer sized chunks

Input chunks from the client exceeding the buffer size would get
truncated. Now we communicate the size of the buffer to the webtty and
it will split the input into buffer sized chunks.

Fixes #1.

js/dist/webtty.d.ts

@@ -9,6 +9,7 @@ export declare const msgPong = "2";
 export declare const msgSetWindowTitle = "3";
 export declare const msgSetPreferences = "4";
 export declare const msgSetReconnect = "5";
+export declare const msgSetBufferSize = "6";
 export interface Terminal {
     info(): {
         columns: number;
@@ -43,6 +44,7 @@ export declare class WebTTY {
     args: string;
     authToken: string;
     reconnect: number;
+    bufSize: number;
     constructor(term: Terminal, connectionFactory: ConnectionFactory, args: string, authToken: string);
     open(): () => void;
 }

js/src/webtty.ts

@@ -11,6 +11,7 @@ export const msgPong = '2';
 export const msgSetWindowTitle = '3';
 export const msgSetPreferences = '4';
 export const msgSetReconnect = '5';
+export const msgSetBufferSize = '6';
 
 
 export interface Terminal {
@@ -48,6 +49,7 @@ export class WebTTY {
     args: string;
     authToken: string;
     reconnect: number;
+    bufSize: number;
 
     constructor(term: Terminal, connectionFactory: ConnectionFactory, args: string, authToken: string) {
         this.term = term;
@@ -55,6 +57,7 @@ export class WebTTY {
         this.args = args;
         this.authToken = authToken;
         this.reconnect = -1;
+        this.bufSize = 1024;
     };
 
     open() {
@@ -90,7 +93,14 @@ export class WebTTY {
 
                 this.term.onInput(
                     (input: string) => {
-                        connection.send(msgInput + input);
+                        // Leave room for message type id
+                        let effectiveBufferSize = this.bufSize - 1;
+
+                        // Split input into buffer sized chunks
+                        for (let i = 0; i < Math.ceil(input.length/effectiveBufferSize); i++) {
+                            let inputChunk = input.substring(i*effectiveBufferSize, Math.min((i+1)*effectiveBufferSize, input.length))
+                            connection.send(msgInput + inputChunk);
+                        }
                     }
                 );
 
@@ -120,6 +130,10 @@ export class WebTTY {
                         console.log("Enabling reconnect: " + autoReconnect + " seconds")
                         this.reconnect = autoReconnect;
                         break;
+                    case msgSetBufferSize:
+                        const bufSize = JSON.parse(payload);
+                        this.bufSize = bufSize;
+                        break;
                 }
             });
 

webtty/message_types.go

@@ -28,4 +28,6 @@ const (
 	SetPreferences = '4'
 	// Make terminal to reconnect
 	SetReconnect = '5'
+	// Set the input buffer size
+	SetBufferSize = '6'
 )

webtty/webtty.go

@@ -115,6 +115,12 @@ func (wt *WebTTY) sendInitializeMessage() error {
 		return errors.Wrapf(err, "failed to send window title")
 	}
 
+	bufSizeMsg, _ := json.Marshal(wt.bufferSize)
+	err = wt.masterWrite(append([]byte{SetBufferSize}, bufSizeMsg...))
+	if err != nil {
+		return errors.Wrapf(err, "failed to send buffer size")
+	}
+
 	if wt.reconnect > 0 {
 		reconnect, _ := json.Marshal(wt.reconnect)
 		err := wt.masterWrite(append([]byte{SetReconnect}, reconnect...))